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  <title>Document</title>
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<body>
  
  <script>
    // ES6之前
    var message1 = "Hello World"
    message1 = "Hello Coderwhy"
    message1 = "aaaaa"
    console.log(message1)

    // ES6开始
    // 1.let
    let message2 = "你好, 世界"
    message2 = "你好, why"
    message2 = 123
    console.log(message2)

    // 2.const
    // const message3 = "nihao, shijie"
    // message3 = "nihao, why"

    // 赋值引用类型
    const info = {
      name: "why",
      age: 18
    }
    // info = {}
    info.name = "kobe"
    console.log(info)


  </script>

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